Hepatitis B vaccination and adolescents: A lost generation

Evolution between 2008 and 2018 of mothers' perception regarding vaccination and infant vaccine coverage in France

OBJECTIVE

Monitoring of vaccination coverage rates (VCRs) is essential to assess the implementation of a country's vaccine policy and its effectiveness. Through the French Vaccinoscopy study, we measured the evolution of VCRs as well as mothers' opinion towards vaccination between 2008 and 2018, before and after implementation of infant mandatory vaccination extension.

METHODS

This is a study based on an internet-standardised questionnaire. In 2018, a representative sample of 3000 mothers of infants 0 to 35 months of age answered on their opinion on vaccination and reported all vaccinations recorded in their child's health record.

RESULTS

On the period considered, infant VCRs were stable and high for diphtheria, tetanus, poliomyelitis, pertussis and pneumococcus components and progressed for measles, mumps rubella, 2 doses at 24 months of age from 45.3% in 2008 to 81.0% in 2018, hepatitis B (HepB) complete primovaccination at 6 months of age from 45.9% in 2008 to 86.3% in 2017 and 95.5% in 2018, and meningococcus C (MenC) 1 dose at 6 months of age from 43.0% in 2017 to 74.2% in 2018. In 2018, 69.0% of mothers were in favour of vaccination while this rate dropped from 80.2% in 2012 to 64.0% in 2017, and 80.8 to 89.6% perceived HepB, MenC measles and pertussis vaccinations as useful/essential, percentages in progress versus 2017.

CONCLUSION

Following the implementation of infant mandatory vaccination in 2018, proportion of mothers in favour of vaccination increased significantly. HepB and MenC VCRs significantly progressed between 2017 and 2018.

Hepatitis B vaccine development and implementation

Vaccination against hepatitis B is the most effective strategy to control HBV infection. The first licensed hepatitis B vaccine was developed by the purification of hepatitis B surface antigen (HBsAg) from plasma of asymptomatic HBsAg carriers. Then, the recombinant DNA technology enabled the development of recombinant hepatitis B vaccine. A series of three doses vaccine can elicit long-term protection more than 30 y. Concurrent use of hepatitis B immunoglobulin and hepatitis B vaccine has substantially reduced the mother-to-child transmission of HBV, nearly zero infection in children of carrier mother with negative hepatitis B e antigen (HBeAg) and 5-10% infection in children of HBeAg-positive mothers. By the end of 2018, 189 countries adopted universal hepatitis B vaccination program, which has dramatically reduced the global prevalence of HBsAg in children <5 y of age, from 4.7% in the prevaccine era to 1.3% in 2015. However, the implementation of universal hepatitis B vaccination in some regions is suboptimal and timely birth dose vaccine is not routinely administered in more than half of newborn infants. Optimal worldwide universal hepatitis B vaccination requires more efforts to overcome the social and economic challenges.

[Prevalence of hepatitis B markers and vaccination status of healthcare personnel: Experience of the Tunis Military Hospital]

BACKGROUND

Hepatitis B is the main cause of liver disease in the world. Chronic hepatitis B may lead to cirrhosis, liver insufficiency or liver cancer. Tunisia is considered as a country with intermediate endemicity, where hepatitis B presents a real public health problem. The aims of this study were to evaluate the prevalence of viral biomarkers of hepatitis B in healthcare personnel; to look for potential risk factors associated with HbS antigen carriage and to evaluate the prevalence of vaccination in this particular population.

METHODS

Sero-epidemiological, prospective and descriptive study, among 2411 healthcare personnel in the Military Hospital of Tunis, during a 5-month period from September 2013 to January 2014.

RESULTS

Blood samples were collected from 1497 volunteers among the hospital staff. Two hundred and seventy-one individuals had a positive HbC antibody titer (prevalence 18.1%), including 229 who were positive for HbC and HbS antibodies (prevalence 15.3%), 12 positive for only HbC antibody (prevalence 0.8%), and 30 positive for HBsAg (prevalence 2%). Among HbS Ag carriers, 56.6% reported needle stick and sharp object injuries during their professional careers. Among HbS Ag carriers, there were three patients with a history of acute viral hepatitis with jaundice, and 27 patients (90%) who were asymptomatic and were diagnosed during our study. Among healthcare workers in the hospital, 56.1% were immunized through vaccination (positive HbS antibodies without HbC antibodies), of whom 66% had durable protective immunity (HbS antibodies>100mU/mL). Lastly, 25.8% of the hospital workers remained without any protection against hepatitis B (serology entirely negative) and were then offered a complete vaccination.

CONCLUSION

Hepatitis B vaccine is the mainstay of hepatitis B prevention. Safe injection practices, blood safety and promoting wider access to monitoring and screening, care and treatment services for hepatitis B are the best guarantees to prevent and control this disease.

Revaccination against hepatitis B in late teenagers who received vaccination during infancy: Yes or no?

The significance of vaccination against hepatitis B during infancy is recognized worldwide, however, whether booster or revaccination after a period of time following the primary vaccination is required remains controversial. Recently, cross-sectional epidemiological surveys found that HBsAg prevalence in subjects born after the implementation of mass vaccination was increased with age, which was attributed to waning of anti-HBs over time. However, comprehensive analysis of the closely related cross-sectional surveys showed that the age-specific increased HBsAg prevalence was more likely associated with the carry-over of the infection occurred in early life, likely due to imperfect coverage of hepatitis B vaccination at the beginning of its introduction. Latest studies showed that booster response could be observed in the majority of individuals vaccinated 30 years ago. Moreover, confirmed breakthrough HBV infection with severe consequences in successfully vaccinated individuals is extremely rare. Thus far no compelling evidence has been acquired to support booster vaccination in adolescence. The uncertainty regarding the duration of protection of hepatitis B vaccination, especially beyond 30 years after the primary vaccination, merits a systematically designed study to follow the same cohort of participants longitudinally, which differs from the cross-sectional studies reported previously, can hopefully offer more direct evidence to help us to determine whether revaccination of hepatitis B vaccine is necessary.

Vaccine criticism: Presence and arguments on French-speaking websites

OBJECTIVE

To evaluate the presence of vaccine criticism on the French Web and to analyze strategies and arguments used by opponents of vaccination.

METHODS

The most frequently used keywords associated with the terms "vaccination" and "vaccine" on Google.fr in September 2013 were identified and searched for individually on Google.fr. The links presented in the first three pages of results were reviewed to identify the most frequent providers of information. The proportion of critical content was determined by website type and a content analysis was performed.

RESULTS

The main preoccupations about vaccination were general concerns; <1% of searches were guided by negative keywords. Institutional websites, healthcare websites, news websites and anti-vaccine websites were the most frequent providers of results. The proportion of anti-vaccine websites among the results was 11% for a neutral search and 24% for a search guided by negative keywords. Critical content was observed in other types of website. Six major strategies and categories of arguments used by opponents of vaccination were identified: the manipulation of science, the use of shocking images and an appeal to emotions via testimonies, a general vaccination conspiracy, the individual's freedom of choice not respected, an unnatural act and a negative benefit/risk balance.

CONCLUSION

It seems important to monitor online vaccination debates, to develop an institutional presence that meets the needs of Internet users and to help them develop a critical view.

[Vaccination against hepatitis B: success and challenges]

Hepatitis B virus is a worldwide leading cause of acute and chronic liver disease including cirrhosis and hepatocellular carcinoma. Effective vaccines have been available since the early '80s. Vaccination against hepatitis B virus infection has proved highly successful in reducing the disease burden, the development of the carrier state and the hepatitis B-related morbidity and mortality in the countries where vaccination has been implemented. Despite success and efficacy of preventive vaccines, a huge number of chronically infected patients still remain. Therapeutic vaccination may prove to be useful coupled with current antivirals and other immunomodulatory approaches to treat these patients. This review summarizes current unresolved issues and future perspectives on vaccination required for global cure of hepatitis B virus infection.

Editorial on "What is a potentially damaging vaccination delay in children younger than 2 years?"

Control of hepatitis B through routine infant immunization in more than 95% of countries has reduced the prevalence of chronic hepatitis carriers to less than 1%-2% in immunized cohorts of children even in high endemicity countries. In that context the authors of this editorial found the results of a paper by Gras et al in this issue concerning. They performed a Delphi survey of 37 French immunization experts and the results concluded that delayed hepatitis B immunization would cause "potential damage" only after 11 years. Large cohorts of French children and adolescents remain susceptible to hepatitis B infection. Given the high rates of immigration to France from areas of higher endemicity, the higher birth rate and degree of integration of these groups into the health system, plus the lower age of sexual debut and the use of injectable drugs in the general population, we cannot agree that a delay of 11 years is acceptable. Rates of adolescent immunization are quite low so relying on protection at this age will yield little in terms of population protection. Loss of confidence in Hepatitis B vaccine following disproved allegations that the vaccine caused Multiple Sclerosis persists in France, and we believe the results of this paper sends a damaging message to health workers and parents in France and beyond.